Abstract:In this study, data from surveys of fishery resources and environments collected from the Bohai Sea ware used to construct an Ecopath model of 1982 and 2014~2015, respectively. Based on the models, we analyzed the trophic impact relationship, structure, and functional parameters of the Bohai Sea ecosystem. Furthermore, we calculated the ecological carrying capacity for Chinese shrimp in the Bohai Sea and compared its changes between the two periods. Trophic impact and keystoness index results showed that the Chinese shrimp was not a keystone species or an important functional group of this ecosystem. Benthic crustaceans, mollusks, and other functional groups occupied important trophic positions in the Bohai Sea ecosystem. The increase in Chinese shrimp biomass will have a negative impact on Oratosquilla oratoria, Portunus trituberculatus, other benthic crustaceans, and polychaetes. The increase in the biomass of functional groups such as Lateolabrax japonicus and gobies may have a negative impact on Chinese shrimp. Network analysis showed that this ecosystem was at an unstable developmental stage during these two periods, and the Bohai Sea ecosystem had higher surplus production. A comparison of the 1982 and 2014~2015 models showed that the maturity and stability of the ecosystem decreased, resulting from its degeneration. The carrying capacity of Chinese shrimp was found to be 0.810 and 0.702 t/km2 in Bohai Sea in 1982 and 2014~2015, respectively. Compared with its current biomass, Chinese shrimp had great potential for continuous enhancement, e.g., by releasing larvae in the Bohai Sea, and the ecological carrying capacity was not exceeded even when the biomass of the Chinese shrimp was increased by 71.68 and 585 fold in 1982 and 2014~2015, respectively. This study provides information for rational implementation of stock enhancement and promotion of sustainable development of fisheries resources in this sea area.
